The core zone of the Yancheng National Natural Reserve (YNNR) in China is the largest wintering habitat of red-crowned cranes (cranes) in the world. However, the invasion of Spartina alterniflora (S. alterniflora) not only changed the original landscape structure of the wetlands but also impacted the cranes’ habitats in the YNNR. In this paper, field investigation data and landscape pattern indices were used to analyze the effects of the S. alterniflora invasion on the habitat quality of wintering cranes. The results indicate that the seep weed (Suaeda salsa) in the natural wetland and the common reed (Phragmites australis) in the managed wetland both provide suitable habitats for cranes. However, the cranes prefer the natural wetland more. The explosive growth of S. alterniflora in the natural area has led to a significant reduction of the cranes’ habitat. The area of crane habitat decreased from 52.07 km2 in 2000 to 22.36 km2 in 2015. As a result of the S. alterniflora invasion, the benthic biomass has declined, which has negatively impacted the quantity and structure of the food utilized by the cranes. This study has both theoretical and practical significance and provides a scientific basis for protecting the wintering habitat of the red-crowned cranes.
Field studies were conducted to investigate arsenic (As), copper (Cu), and zinc (Zn) contamination in agricultural soils and wheat crops at two areas in Huaibei, China. Area A is in the proximity of Shuoli coal mine. In area B, three coal mines and a coal cleaning plant were distributed. The potential health risk of As, Cu, and Zn exposure to the local inhabitants through consumption of wheat grains was also estimated. The results showed that significantly higher (p?<?0.05) concentrations of As, Cu, and Zn were found in soils collected from area B than in those from area A. Arsenic concentrations in wheat sampled from area A were negatively correlated with the distance from the coal mine (p?<?0.001). Concentrations of Cu and Zn in wheat seedlings and grains collected from area B were significantly higher (p?<?0.05) than in those collected from area A, with the exception of Zn in wheat seedlings. Concentrations of Cu and Zn in most wheat grain samples were above the permissible limits of Cu and Zn in edible plants set by the Food and Agriculture Organization/World Health Organization. The hazard index of aggregate risk through consumption of wheat grains was 2.3–2.4 for rural inhabitants and 1.4–1.5 for urban inhabitants. The average intake of inorganic As for rural inhabitants in Huaibei was above 10 μg day?1. These findings indicated that the inhabitants around the coal mine are experiencing a significant potential health risk due to the consumption of locally grown wheat. 相似文献
Abstract This paper concerns the incineration of isopropyl alcohol (IPA) using the ferrospinel catalyst MnFe2O4. It covers the preparation of the ferrospinel catalyst, the screening of catalytic activity, catalytic incineration testing, and 72-hr decay testing of the catalyst. The experimental results of catalyst screening reveal that the Mn/Fe catalyst is the best of five prepared catalysts (chromium/iron [Cr/Fe], manganese/iron [Mn/Fe], zinc/iron [Zn/Fe], nickel/iron [Ni/Fe], and pure magnetite [Fe3O4]). In tests of the catalytic incineration system used to convert IPA, 98% conversion was obtained at a space velocity of 24,000 hr?1, an oxygen (O2) content of 21%, 1700 ppm of IPA, and a reaction temperature of 200 °C. 相似文献
Large-scale incinerators are applied widely as a result of the heavy burden of municipal solid waste(MSW) generated, while strong opposition is arising from the public living nearby. A large-scale working incineration plant of 1500 ton/day was chosen for evaluation using life cycle assessment. It was found that the corresponding human toxicity impacts via soil(HTs), human toxicity impacts via water(HTw) and human toxicity impacts via air(HTa)categories are 0.213, 2.171, and 0.012 personal equivalents(PE), and global warming(GW100)and nutrient enrichment(NE) impacts are 0.002 and 0.001 PE per ton of waste burned for this plant. Heavy metals in flue gas, such as Hg and Pb, are the two dominant contributors to the toxicity impact categories, and energy recovery could reduce the GW100 and NE greatly. The corresponding HTs, HTw and HTa decrease to 0.087, 0.911 and 0.008 PE, and GW100 turns into savings of- 0.007 PE due to the increase of the heating value from 3935 to5811 k J/kg, if a trommel screener of 40 mm mesh size is used to pre-separate MSW. MSW sorting and the reduction of water content by physical pressure might be two promising pre-treatment methods to improve the combustion performance, and the application of stricter standards for leachate discharge and the flue gas purification process are two critical factors for improvement of the environmental profile identified in this work. 相似文献
As one of the largest human activities, World Expo is an important source of anthropogenic Greenhouse Gas emission (GHG), and the GHG emission and other environmental impacts of the Expo Shanghai 2010, where around 59,397 tons of waste was generated during 184 Expo running days, were assessed by life cycle assessment (LCA). Two scenarios, i.e., the actual and expected figures of the waste sector, were assessed and compared, and 124.01 kg CO2-equivalent (CO2-eq.), 4.43 kg SO2-eq., 4.88 kg NO3--eq., and 3509 m3 water per ton tourist waste were found to be released in terms of global warming (GW), acidification (AC), nutrient enrichment (NE) and spoiled groundwater resources (SGWR), respectively. The total GHG emission was around 3499 ton CO2-eq. from the waste sector in Expo Park, among which 86.47% was generated during the waste landfilling at the rate of 107.24 kg CO2-eq., and CH4, CO and other hydrocarbons (HC) were the main contributors. If the waste sorting process had been implemented according to the plan scenario, around 497 ton CO2-eq. savings could have been attained. Unlike municipal solid waste, with more organic matter content, an incineration plant is more suitable for tourist waste disposal due to its high heating value, from the GHG reduction perspective. 相似文献
The refuse in landfills becomes stabilized or aged after years of placement, and the resultant partly or fully stabilized refuse thus obtained is referred to as "aged refuse" in this work. The aged refuse contains a wide spectrum and large quantity of microorganisms, which have been proved to have a strong decomposition capability for both biodegradable and refractory organic matter present in some wastewaters. In this study, the aged refuse excavated from a 10-year old closed landfill compartment at Shanghai Refuse Landfill was used as the substrate in a bioreactor for the biofiltration of sewage taken from the sewage pipeline systems in Shanghai downtown areas. Typically, 120kg of screened aged refuse with a diameter less than 15mm was used as biofiltration material in a round shaped bioreactor with an inner diameter of 80cm and a height of 150cm. Influent sewage with initial COD, BOD, and NH(3)-N concentrations of 400-500, 240-300, and 45-50mg/L, respectively, was introduced into the bioreactor. The corresponding concentrations in the effluent were reduced to below 80-100, 10-20, and 10-15mg/L, respectively, at a hydraulic load of 1000-1200L/m(3) refuse/day, and the treatment efficiencies decreased with increased hydraulic load. The treatment mechanism was also studied. It was found that the pollutant removal efficiencies dramatically decreased when the aged refuse in the bioreactor was preliminarily disinfected using NaClO solutions, indicating that the pollutants in the sewage were biologically removed. The treatment process developed in this work is cost-effective. 相似文献
In this work, rhodamine-related fluorescence was measured on-line at four reactor heights in order to study hydrodynamics within an upflow anaerobic sludge bed reactor. A linear dependence of the dispersion coefficient (D) on the upflow velocity was observed, while the influence of the organic loading rate (OLR) was insignificant. Furthermore, the Bodenstein number of the reactor loaded with granulated sludge was found to be position-dependent with the largest values measured at the bottom of the sludge bed. This trend was not observed in the reactor without sludge. Chemical oxygen demand (COD) and volatile fatty acid (VFA) concentrations were measured at the same reactor heights as in rhodamine tests using conventional off-line analytical methods and on-line multiwavelength fluorometry. Significant spatial COD and VFA gradients were observed at organic loading rates above 6g COD l(R)(-1)d(-1) and linear upflow velocities below 0.8m h(-1). 相似文献